B4J Tutorial [IoT][ESP8266]B4J/B4A/B4i & ESP8266 Basic: Example thread

inakigarm · Apr 29, 2016

Thanks !!
Only waiting for B4R integration

KMatle · Apr 29, 2016

Another one:

The ESP8266 can send http get requests by:

B4X:

print wget("192.168.178.23/esp/test.php?Name=Peter&Age=55")

php-Script:

B4X:

<?php
$name=$_GET["Name"];
$age=$_GET["Age"];

print $name . " is " . $age . " years old...";
?>

Output:

B4X:

Peter is 55 years old...
Done...

KMatle · May 1, 2016

Checking GPIO's by interrupt and if a change occurs call a php script (get request):

B4X:

st = 0
p = 2
Pi p st
print "ESP ist waiting for Pin " & p & " to change..."
interrupt p [gpio]
Wait
[gpio]
Pi p nst
print st & "/" & nst
print wget("192.168.178.23/esp/pin.php?Pin=2&Status=" & nst)
st = nst
wait

PHP:

B4X:

<?php
$pin=$_GET["Pin"];
$st=$_GET["Status"];
print "Back from PHP -> Pin: " . $pin . " has changed: " . $st;
?>

Just click on "Run" in the ESP's menu and refresh the browsers page to see the messages (or add some code to the php to store/use the data)

Known issue: A space is used to delimit the get request:

B4X:

wget("192.168.178.23/esp/pin.php?Name=Muller&Street=Muller Street)

will truncate the request after "Street=Muller". I've contacted the author to fix this.

rwblinn · May 1, 2016

Thanks = Very well written. Just ordered one for testing [as always curious how to use]

KMatle · May 3, 2016

rwblinn said:
Just ordered one for testing

Please feel free to copy it to your "HowTo" page.

KMatle · May 4, 2016

Check GPIO pin by interrupt and store the events into a MySQL database. The special chars äöüß are encoded correct except space which will be converted to a "+".

ESP-Basic program:

B4X:

dev = "ESP1"
st = 0
p = 2
Pi p st
print "ESP ist waiting for Pin " & p & " to change..."
interrupt p [gpio]
Wait
[gpio]
Pi p nst
if nst = 0 then
   url = "192.168.178.23/esp/pin.php?Action=Message&mfrom=" & dev & "&mto=System&mtype=1&mess=Door/Window opened"
   gosub [urlencode]
   print wget(url)
else
   url = "192.168.178.23/esp/pin.php?Action=Message&mfrom=" & dev & "&mto=System&mtype=2&mess=Door/Window closed"
   gosub [urlencode]
   print wget(url)
end if
st = nst
wait

[urlencode]
url = replace(url," ", "+")
print url
return

PHP:

B4X:

<?php

$host = "127.0.0.1";
$user = "homeauto";
$pw = "homeauto";
$db = "HomeAuto";

$con = mysqli_connect($host,$user,$pw) or die(mysqli_error());
mysqli_select_db($con,$db) or die(mysqli_error());
mysqli_query($con,"SET CHARACTER SET utf8");
mysqli_query($con,"SET NAMES 'utf8'");

$action=$_GET["Action"];

switch ($action) {
    Case "Message":
         $mfrom=$_GET["mfrom"];
        $mto=$_GET["mto"];
        $mtype=$_GET["mtype"];
        $mess=$_GET["mess"];
  
        $r = mysqli_query($con, "Insert into mess (st, mfrom, mto, mtype, mess) VALUES ('I', '$mfrom', '$mto', '$mtype', '$mess')") or die(mysqli_error());
        print $mess . "OK";
        break;

Case "GetMessages":
        $q = mysqli_query($con,"SELECT * FROM mess where mtype = '1' order by ts desc") or die(mysqli_error());
      
        $rows = array();
        while($r = mysqli_fetch_assoc($q))
        {
            $rows[] = $r;
        }
      
        $jsrows=json_encode($rows);
        print $jsrows;
        break;
  
default:
        print json_encode ("Error: Function not defined ->" . $action);
}

?>

Hardware:

Connect "D4" (= GPIO2) to a button and from the button to ground (the black square on the left

) The USB cable is used for the power supply.

Table (dump file, just import it via the phpadmin gui):

B4X:

-- phpMyAdmin SQL Dump
-- version 4.5.1
-- http://www.phpmyadmin.net
--
-- Host: 127.0.0.1
-- Erstellungszeit: 04. Mai 2016 um 16:29
-- Server-Version: 10.1.10-MariaDB
-- PHP-Version: 5.6.15

SET SQL_MODE = "NO_AUTO_VALUE_ON_ZERO";
SET time_zone = "+00:00";


/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
/*!40101 SET NAMES utf8mb4 */;

--
-- Datenbank: `homeauto`
--

-- --------------------------------------------------------

--
-- Tabellenstruktur für Tabelle `mess`
--

CREATE TABLE `mess` (
  `nr` int(11) NOT NULL,
  `st` varchar(200) COLLATE utf8_unicode_ci NOT NULL,
  `ts` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  `mfrom` varchar(150) COLLATE utf8_unicode_ci NOT NULL,
  `mto` varchar(150) COLLATE utf8_unicode_ci NOT NULL,
  `mtype` varchar(200) COLLATE utf8_unicode_ci NOT NULL,
  `mess` varchar(2000) COLLATE utf8_unicode_ci NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

--
-- Daten für Tabelle `mess`
--

INSERT INTO `mess` (`nr`, `st`, `ts`, `mfrom`, `mto`, `mtype`, `mess`) VALUES
(32, 'I', '2016-05-04 14:18:34', 'ESP1', 'System', '1', 'Door/Window opened'),
(33, 'I', '2016-05-04 14:18:34', 'ESP1', 'System', '2', 'Door/Window closed');

--
-- Indizes der exportierten Tabellen
--

--
-- Indizes für die Tabelle `mess`
--
ALTER TABLE `mess`
  ADD PRIMARY KEY (`nr`),
  ADD UNIQUE KEY `nr` (`nr`),
  ADD KEY `mto` (`mto`);

--
-- AUTO_INCREMENT für exportierte Tabellen
--

--
-- AUTO_INCREMENT für Tabelle `mess`
--
ALTER TABLE `mess`
  MODIFY `nr` int(11) NOT NULL AUTO_INCREMENT, AUTO_INCREMENT=34;
/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;
/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;
/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;

Usage:

1. click on run to start the program (webbrowser)

2. press the button on the board

3. update the browser to see the output of the print commands (not needed)

4. take a look at the table:

rwblinn · May 5, 2016

A first test after receiving a NodeMCU. Connected DHT11 sensor and send data via UDP to B4J UDP Client.
ESP8266 Basic is in Alpha Release, hope to see functionality like wpost (to send data to B4J Webserver), JSON (in the pipeline) etc.. This is a good read to get the latest on development, plus the documentation.
Really fun to play with this neat controller.

Screenshot UDP test after running ESP8266 Basic Code.

ESP8266 Basic Code

B4X:

'ESP8266 NodeMCU HowTo - Get Temperature and Humidity from DHT11 sensor
'Connection:
'DHT11 ---- ESP8266
'GND ------ GND
'VCC ------ 3.3v
'Signal --- D4

'Set the sensor model (DHT11) and pin (D4)
dht.setup(11, D4)

print "ESP8266 NodeMCU HowTo - Get Temperature and Humidity from DHT11 sensor"

'Get the temperature in celsius
celsius = dht.temp()
print "Temperature " & celsius & "C"

'Get the humidity
humidity = dht.hum()
print "Humidity " & humidity & "%"

'Send data to UDP client
udpwrite "192.168.0.4", 3661, "Temperature " & celsius & "C, Humidity " & humidity

B4J UDP Client
Attached - used Client1 for receiving data from the NodeMCU.

Thanks again for triggering this topic.

KMatle · May 5, 2016

rwblinn said:
Really fun to play with this neat controller

Yep. I like the idea of the "all in one" idea of it. No need for an external sdk, libs, etc. Just input a few lines of code and have fun. And the price is unbeatable

A perfect device for B4x

rwblinn · May 14, 2016

For those interested, started to build a webpage about ESP8266 Basic including sample projects.
The sample projects include interaction with B4J in various ways (UI, Server).

Select from my homepage IoT > ESP8266 > ESP8266 Basic Experiments.

rwblinn · May 16, 2016

Explored further the integration between the ESP8266 and B4J.
This is an example of reading DHT11 sensor data from an ESP8266 , send the data (by ESP82266 Basic program) to a B4J server application which stores the data and displays in a Google Line Chart. Every time new data arrives at the B4J server, the Google Line Chart is automatic refreshed in the Webbrowser (fun watchin' it...). Again, this shows the power of B4J = few lines of code and magic happens

KMatle · May 29, 2016

So what is the RB good for?

I changed the thread's title a bit (could be a sticky thread for the ESP)

B4J Tutorial [IoT][ESP8266]B4J/B4A/B4i & ESP8266 Basic: Example thread

inakigarm

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